Datasheet

KSZ8081MNX/RNB
DS00002202A-page 4  2016 Microchip Technology Inc.
1.0 INTRODUCTION
1.1 General Description
The KSZ8081 is a single-supply 10BASE-T/100BASE-TX Ethernet physical-layer transceiver for transmission and
reception of data over standard CAT-5 unshielded twisted pair (UTP) cable.
The KSZ8081 is a highly-integrated PHY solution. It reduces board cost and simplifies board layout by using on-chip
termination resistors for the differential pairs and by integrating a low-noise regulator to supply the 1.2V core.
The KSZ8081MNX offers the Media Independent Interface (MII) and the KSZ8081RNB offers the Reduced Media Inde-
pendent Interface (RMII) for direct connection with MII/RMII-compliant Ethernet MAC processors and switches.
A 25 MHz crystal is used to generate all required clocks, including the 50 MHz RMII reference clock output for the
KSZ8081RNB.
The KSZ8081 provides diagnostic features to facilitate system bring-up and debugging in production testing and in prod-
uct deployment. Parametric NAND tree support enables fault detection between KSZ8081 I/Os and the board. LinkMD
®
TDR-based cable diagnostics identify faulty copper cabling.
The KSZ8081MNX and KSZ8081RNB are available in 32-pin, lead-free QFN packages.
FIGURE 1-1: FUNCTIONAL BLOCK DIAGRAM
KSZ8081MNX/
KSZ8081RNB
MAGNETICS
RJ-45
CONNECTOR
MEDIA TYPES:
10BASE-T
100BASE-TX
ON-CHIP TERMINATION
RESISTORS
MII/RMII
MDC/ MDIO
MANAGEMENT
XO
XI
25MHz
XTAL
22pF
22pF
10/100Mbps
MII/RMII MAC
50MHz
(KSZ8081RNB)
REF_CLK